chore(package): update dotenv to version 8.1.0

Closes #47

Author: greenkeeper[bot]

package.json

@@ -26,7 +26,7 @@
     "@types/supertest": "^2.0.6",
     "coveralls": "^3.0.0",
     "del-cli": "^1.1.0",
-    "dotenv": "^6.1.0",
+    "dotenv": "^8.1.0",
     "jest": "^23.6.0",
     "nodemon": "^1.18.5",
     "nsp": "^3.1.0",